These days, a screen size of a liquid-crystal display device such as a thin type television is becoming larger, and products having a screen size of, for example, a 60-inch type, a 70-inch type and an 80-inch type are sold. In such a liquid-crystal display device, one which uses an LED (Light Emitting Diode) as a backlight light source instead of a conventional fluorescent tube is most commonly used. Moreover, the liquid-crystal display device is used not only for a television but in various applications such as a monitor of a PC (personal computer) and a digital signage (electronic sign), and the LED is also required to have higher luminance (higher output power) accordingly.
In the above liquid-crystal display device, radiation countermeasures of the LED need to be carried out because an amount of heat generation also increases as the LED has higher luminance. For example, Patent Document 1 describes a structure that an LED substrate in which an LED serving as a heat source is arranged is attached to a heat radiation member made of aluminum called heat sink (also referred to as heat spreader) for dissipating heat from the LED. Further, Patent Document 2 describes a structure that a heat radiation member is provided behind a back face chassis (also referred to as backlight chassis) provided on a back face side of a light-guide plate.